Don’t return false for blank glyphs

CTFontCreatePathForGlyph() will return NULL for blank glyphs causing
CoreTextStyle::GetGlyphOutline() to return false which propagated as
error all the way to OutputDevice::GetTextOutlines() causing it to
needlessly enter into fallback code. Other implementations just return
true and an empty polygon here.

Change-Id: Ib20ebff00f7cb3aae22f1c6b4c3a0e9d7a429987
Reviewed-on: https://gerrit.libreoffice.org/31902Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Khaled Hosny <khaledhosny@eglug.org>

vcl/quartz/ctfonts.cxx

@@ -231,6 +231,19 @@ bool CoreTextStyle::GetGlyphOutline(const GlyphItem& rGlyph, basegfx::B2DPolyPol
 
     CGGlyph nCGGlyph = rGlyph.maGlyphId;
     CTFontRef pCTFont = static_cast<CTFontRef>(CFDictionaryGetValue( mpStyleDict, kCTFontAttributeName ));
+
+    SAL_WNODEPRECATED_DECLARATIONS_PUSH
+    const CTFontOrientation aFontOrientation = kCTFontDefaultOrientation;
+    SAL_WNODEPRECATED_DECLARATIONS_POP
+    CGRect aCGRect = CTFontGetBoundingRectsForGlyphs(pCTFont, aFontOrientation, &nCGGlyph, nullptr, 1);
+
+    if (!CGRectIsNull(aCGRect) && CGRectIsEmpty(aCGRect))
+    {
+        // CTFontCreatePathForGlyph returns NULL for blank glyphs, but we want
+        // to return true for them.
+        return true;
+    }
+
     CGPathRef xPath = CTFontCreatePathForGlyph( pCTFont, nCGGlyph, nullptr );
     if (!xPath)
     {